Wood planing machine



Dec. 14, 1937. F. A. NICHOLSON ET AL. 2,102,186

3 sheets-sheet 1 Filed July 20, 1956 WOOD PLANING MACHINE l\ INVENTORS.

. Muvo? TPR/rc//Mo ATTORNEY.

Dec. 14,y 1937,

F. A. NICHOLSON ET AL.

WOOD PLANI NG MACHINE Dec. 14, 1937. F. A. NICHOLSON ET AL.

WOOD PLANI NG MACH INE Filed July 20, 1936 3 Sheets-Sheet 3 the trees.

l snipped ends.

- ciency.

alented Dec. 14. i937 Aoon maniac Macl- FrederickA. Nicholson and Wilmot 'l. lPritchai-d,

Seattle, Wash., 'assignors toStctson-Ross 1Viachine Company, Seattle, ash., av corporation of Washington Application .luly 20, i936, Serial No. 91,568

l2 Claims.

Our invention relates toA a method of planing wood and a Wood planing machine for carrying out said method. More particularly, our invenf` tion relates to a novel method and a novel planing device to provide smooth flat suriacesvon a board and to plane the board'to an exact'predetermined thickness.

It must be remembered that the wood stock delivered to the ilnishing or planing machine is the stock which is almost the final product from In other words, the cost, of logging, transportation, sawing and the like have all'been accumulated against this stock. In the event that any of the stock is wasted by an inellcient method or by an imperfect planing machine, such stock as well as the cost previously expended or accountable against a particular piece of stock becomes lost.' It is, therefore, of primary importance that all Waste which has been heretofore caused by the methods used and the planing devices on the market shall be eliminated, and thata vmethod and a device be provided having extreme veili- 1. One great source of waste underpresent mehr ods of planing lumber and machines used is that or placing the same under a longitudinal strain which holds the lumber vfirmly against iluttering and vibration, substantially prevents end snipl ping, provides a better grade of planing or finishing, and permits the machine to run at a greatly s increased rate of production.`

Wastage of lumber in the commercial operation of machines of theprior art exceedsf or f per cent of the total output. `A large .portion of this wastag'e is brought about b y reason of snipped ends.` The-wastageof lumber by machines embodying our invention has been reduced atleast fifty per cent and on our machines there is no substantial wastageof lumber by reason of Another .dilliculty found in the prior art rhachines is the lack o f uniformity of thickness of the resulting products. Planing machines of the prior art aspresently used provide-a product,

vwhich pro'duct commonly varies in thickness from a predetermined thickness by an amount as great as onesixty-'fourth of anjincli and often as great as one thirtysecond of an'minch. It is an object of our invention to 'substantially overcome (ci. iii-iis) this variation in thickness and provide a product of substantially uniform thickness.

The double surfacing planing machines of th prior art, operating on the higher grades of kiln dried lumber, were generally operated with a maximum rate of production of approximately two` hundred and fifty lineal feet a minute and only a few under ideal conditions operated on a similar class of lumber at a. speed of four hundred and fifty lineal feet a minute, with resultant increased losses. Machines embodying ourinvention are now operating on a similar class of lumber with a normal rate of production of five hundred'and flfty lineal feet a minute'. By imparting a exing in the lumber, we have provided for utilizing the longitudinal stiffness of the ich lumber and machines embodying our invention not only normally may be operated at greatly increased speeds as compared to prior art machines, but our machines produce, with a high degree of efficiency, a superior'grade of lumber. 'I'his high degree of eiliciency and superior grade of lumber is maintained in our machines despite our increased speeds. v

Another diiiiculty found in the prior art machines is that lumber tends to bind in passing through the machine as the cutting'knives be come dull. Bed plates have been spaced apart a predetermined vdistance sumcient to provide a passageway of afsize to permit a piece of lumber of a predetermined thickness to pass therethrough with only enough' clearance for a snug sliding fit. As the knives dulled or wore away, the thickness of the board increased, causing thevboard to bind and causing what ls usually called in, the trade a #tight feed. This was not changed in prior art machines by increasing the clearance of the sliding fit as thlsvwould permit the boards to iiutter or vibrate resulting in uneven cutting action.. In ourl device, we position thebeds apart atsuch a distance to provide a psageway oi' size substantially greater than thethlckness of the board and flex/the board from one bed to the other. Thus even if the thickness of the board increases upon dulling of the knives, the board is still of a thickness less than the size of the passageway and thus, at all times, we provide free or loose feeding.` K

Free feeding in planing machines is funda-4 f mentally important for the following reasons:

First; lumber usually run on such machines is' feedingstrains are required, numerous breakages 2 y i arcanes occur with consequent destruction of material and delay in operation. Second, if there is any obstruction to the feeding of the material, added pressure is required of the feeding means so as to 5 supply firmer grip upon the lumber to force it against and through regardless of the obstruction, and this added pressure crushes the grain on the surfaceof the lumber and immediately causes undue compression of the grain of the woodl which, subsequentl to planing operation upon release of pressure, expands and results in what is called raised grain.

It is also necessary thatl lumber must be caused to travel uniformly to prevent burning or l gouging by the knives occurring during stoppages, and furthermore, if the lumber is not totally stopped and only slowed down, still there is a bad eect, due to lack of uniformity of knife ac-v` tion upon the lumber. For these reasons it is necessary to provide free feeding.

The standard grading rules `of the lumber industry permit of skipped spots on the back of certain patterns of lumber, providing such stock measures full thickness; In the manufacture of such lumber great efforts have been made to take advantage ofthis grading rule to salvage thin stock that did not contain suilicient thickness to permit of surfacing two sides. Some attempts were made in this direction by running such stock face down taking a fixed cut on the face side, so that the skipped surface would be on'the back. This method proved a failure for the reason that at such skipped portions, the upper or thicknessing cutter head was not functioning, and was in itself evidence that the stock was not of uniform thickness. It is a purpose in the invention disclosed to produce a uniform thickness of stock with one side only surfaced, that being the face side, and even though the 40 back be skipped at spots or the full length of board, such stock would be up to full thickness and thus all value conserved.

. It is important to note that when thin stock is being planed, our invention surfaces to thickness on less than a full reserved cut, and that an appreciable amount of lumber Vis salvaged by thus operating between the limited predetermined cut and the minimum cut.

In sawing lumber, an attempt is made to provide a: thickness having sucient surplus over the desired finished thickness to permit the lumber to be properly surfaced on both sides. In the prior art commercial planing machines, one cutter head takes a predetermined cut either from the face or back of the lumber, and the other cutter head attempts to size or determine the thickness of the stock. Contrasted with such operation, in our device the lumber is urged away from one cutter head against a bed plate and thick- 'nessed to an initial predetermined thickness and then placed under longitudinal strain orK flexed and urged in the opposite direction away from a thinner byour machine, directly contrary to theprior .artpracticea and the full value of such ,f, /thln stock is retained so that it may be used to 75\ produce the maximum thickness oi' stock obtaintoo thin to.

able therefrom. Also in our machine if the rough stock has a small surplus sufficient only for planing one side, such surplus is reserved for finishing the face, and when this surplus is planed oi, a perfect face and exact predetermined thickness of stock is provided. When the surplus increases over the predetermined preliminary maximum thickness desired, this surplus is planed from the back of the stock. Thus the cutter head which finishes the face of the 10 Stock operates under ideal conditions, taking a predetermined almost constant depth of cut and provides a better face.

Furthermore, by providing a predetermined maximum cut on the surface of the face of the 15 stock, and cutting all excess from the back of the stock, we have minimized the tendency of the face to cup or warp and become concave when the moisture content of the stock is reduced subsequent to planing. Lumber stock which is be- 2O ing planed usuallyA has a relatively dry surface and a content of moisture increasing towards the center of the stock. When a heavy cut is taken from a surface of such stock and that surface `later dries out, shrinkage occurs tending to con- 25 cave that surface. By providing a minimum cut on the face surface, we produce a minimum shrinkage on the face surface and a minimum tendency of that surface of the lumber to concave as the lumber dries out. Also, any thick 30 cuts which may become necessary in removing surplus stock are taken from the back so that if the lumber tends to warp in drying, the back of the lumber will be concaved instead of the face. In that event, such concaving on the back .30 of the lumber will not cause cracks in the surface of the flooring or other surfaces where finished lumber is used.

Asone of the primary factors in the grading of lumber is the quality of the face surface, it is 40 desirable that the face surface be run face up so that it may be readily examined by the graders and the grade determined. Furthermore, if all excess is rst removed from the back of the lum-l ber, which is one of the objectives attained in 45 our invention, a smooth support is provided against which better surface facing can be obtained and a constant, practically uniform i amount of stockis left to be removed by the cutterhead producing the face surface. On some 50 patterns of lumber after the stock leaves the surfacing units of the machine, it goes through matcher heads, which form tongues and grooves or other shapes on the edges of the lumber. If the lumber is not perfectly thicknessed, it is apparent that the iiooring, or the liunber having "other pattern thereon, will not be uniform'and level, and that the patterns, as the tongues and grooves, will not properly match. It is also for this reason that the quality and value of the 60 `lumber depends in a large degree upon the accurate thicknessing of the same.

'I'he cpmmercial two lside surfacing machines of the prior art included a. lower cutter head which removed a predetermined fixed cut and an upper cutter head which removed the excess and thicknessed the stock. In some instances the upper cutter head cut last and thicknessed the stock after a predetermined cut had been removed from the bottom and in some instances the upper cutter head cut first and thicknessed the stock toys. thickness which included a fixedy amountl reserved to be removed by the lower cutter head.

When lumber was run face up in such'prior art machines, the face of the stock could be readi- 2,109,158@ l it iy examined to determine whether the thicknessing operation had been performed. Howeven as sawn lumber is produced thick and thin,- many boards do not contain suiiicient thickness to permit finishing both faces. Therefore if suncient excess was present to surface one face, this was removed from the back and the face was not surfaced so the stock was thrown out or degraded. When lumber was run face do-wn, of coursel the face could not be readily examined for grading purposes. Next when the face was produced by a fixed cut regardless of the thickness of the stock, any failure of such cutter head to cut, as by skip spots, etc. indicated that the thieknessing operation had not been completely performed and the stock was again thrown out or degraded.

It is therefore important to note that in all such machines, irrespective of whether the lower cutter head cut rst or last, that if the lumber wasr not uniformly surfaced by the thicknessing cutter head, after a predetermined amount was removed or reserved to be removed, such stock was not of a uniform predetermined thickness, regardless of whether the stock was run face up or face down.

In an attempt to obtain an exact predetermined thickness in such prior art machines, lumber was.

generally run face up and the cutter head, which cut the face, was the thicknessing cutter head, while the lower cutter head, which cut the back, removed a predetermined xed amount. Therefore if the face of the stock was not surfaced, this indicated that the thicknessing operation had not been performed.

Contrasted with the prior art machines, our invention comprises a method and a machine for sible for the stock, if the same is to be matched (i. e., provided with" tongues or grooves or other formed edges), to be held continuously in a true -position while the tonguing and grooving heads r are functioning, and thus accurate matching is accomplished. even though the lumber may be partly or wholly rough on the back.

Again referring to two side surfacing machines of the prior art, such machines resulted in heavy or-light cuts (depending on the thickness of the rough stock) being removed from the face. When Ltoo light a cut was taken, the face surfacing knives were cutting in the grit (such grit naturally accumulates. in the rough surface of the stock when it i-s in storage) andthe knives were rapidly dulied. On the other hand, when too heavy a cut was taken, such knives were doing more cutting than advisable to permit thev highest degree of i `eiiicient surfacing. Such cuttingresulted in poor finishing of the face and required very frequent sharpening and adjusting o-f the cutter knives to provide the degree of exactness of thicknessing required. Further, such operation when surfacing thick stock resulted in the cupping or concaving of the face when the .lumber later dried out because of the heavy cut taken from the face of the stock.

It is the object of our invention to overcome the above difficulties in the art and provide a novel method and device accomplishing the hereinbefore mentioned desirable features.

The above mentioned general objects of our in- -vention, together with others inherent in the exemplary fori''s oi' embodiment of our invention, throughout which drawings like reference numerals indicate like'parts:

Figure 1 is a, view in longitudinal vertical section with parts shown in elevation of a planer or planing machine constructed in accordance with this invention, and operatively showing in said planing machine lumber of a sumcient thickness So that a. cut is taken oif of both the back and face of said lumber;

Figure 2 is a similar view with parts broken away showing in the machine lumber of lesser thickness on which no full cut is taken from the back, but a 'full nishing cut is taken from the face of the lumber;

Figure 3 is a similar view with parts broken away, showing in .the machine a relatively thin piece of lumber which 'passes through the machine without being planed on either back or face;

Figure i is a fragmentary sectional view illustrating a modied form of the invention showing a presser means positioned after the face finishing cutter head;

Figure 5 is an end elevation of a piece of unnished lumber illustrating diagrammatically the location and distribution of the moisture content in said lumber, indicating in dotted lines the cuts which may be takenoif of the face and back of said lumber in finishing;

Figure 6 is a View in end elevation showing a plurality of finished pieces of lumber as flooring 'and showing the seams which result due to shrinkage and warpage, which seams are closed at the face and open at the back when several of said pieces of lumber are assembled as in forming a floor; Y

Figure 7 is a reduced fragmentary plan view on line '1 -'I of Figure 1 showing parts of the frame and mounting members;

Figure 8 is a view substantially on broken line t-ii of Figure 1; and

Figure 9 is a fragmentary plan view, withparts in section, substantiallyl on broken line 9-9 of Figure 2.

A longitudinal passageway it for receiving therethrough traveling lumber is provided between upper bed plate II and lower bed plate I2. In our invention the depth of this passageway is adjusted to be substantially greater than the size mf the lumber passing therethrough and the lumber is flexed as it is urgd against one bed while passing the same and then urged against the other while passing such bed.

Both upper bed plate II and lower bed plate I2 are fixed during the operation of the machine. Also the said beds are adjustably mounted for relative movement toward and away from` each other. Also the cutter headsA I3 and I4 are likewise adjustably mounted for relative movement toward 'and away from each other. The adjustment ofthe cutter heads may be with or independent of the bed plates. This may be accomplished by means and for purposes hereinafter discussed'.

We haveillustrated driyen feed rolls I5 and I6, which may be driven by any suitable means (not shown), for urging the lumber through the machine, and driven 'feed rolls I'I and I8, which may be likewise 'driven by any suitable means (not shown), for removing lumber from the machine. We wish it expressly understood that we do not limit ourselves to driven feed rolls, as any of the usual feeding devices on the market may be used in connection with our machine.

It has been common practice to provide driven feed rolls or driven feed beds or a combination of the two, and we have set forth driven feed rollsvonly as an illustration of feeding means. Furthermore, the driven feed rolls I1 and I8 may be eliminated if the device is in continuous operation, as each succeeding piece of lumber stock Will force the piece of stock preceding it through posed in operative spaced relation to the upper feed bed I I. We have illustrated such a planing device by means of a driven cutter head I3f provided with the usual knives I 9. As illustrative of an adjustable support for the' cutter head I3, it may have each'end mounted vonvertically adjustable frames 20, which are slidingly supported on the main frame 2I. (See Figs. 1 and 9.) An adjusting screw 22 may be threaded into each adjustable frame 20. Each adjusting screw 22 is journaled in lugs 23 on mainframe 2I and has a Worm wheel 24 secured thereon and positioned between the lugs 23. A worm 25 engages each worm wheel 24 anda transverse shaft 26 is operably connected with worm 25. The frames 20, screws 22, worm wheels 24 and worms 25 are in duplicate on the respective sides of the machine. The cutter head I3 may bevertically adjusted relative to bed I2 by angularly moving adjusting screws 22 for purposes hereinafter discussed. Pressure means are operatively positioned as respects the cutter head I3 and provide' means for urging the lumber stock away from the cutter head I3 and against the upper bed II. Such pressure means are positioned on either side of the cutter head I3 as is indicated by pressure means 21 and 28. Pressure means 21 preceding Ythe cutter head I3 as respects lumber stock entering themachi'ne, is preferably composed of members 29 and 30. Pressure members 29v and 30,'. preferably having pivotally mounted pressure shoes 3| and 32 respectively on the upper ends thereof, are positioned to engage the lower surface of the stock entering the machine and urge the stock upwardly against bed plate II. Pressure member 29 is pivotally connected to one end portion ofthe shoe 3I and the other end portion of the shoe 3I is pivotally secured to link 33.` Link 33 is resiliently supported through l ber 29 is guided for'vertical movement by links 39 and 40, which links are`pivotally secured to the main frame 2I and pivotally secured on their other end portions to the pressure member 29. The pressure member'29, which has been just described, affords a shoe 3I which will resiliently urge lumber stock upwardly against the bed II and has it's respective end portions urgedupwardly together and separately, thereby permitting the shoe 3| to maintain an angular positimurging the end portion of one piece of lumber stock, and also urging upwardly another piece of succeeding lumber stock of a different thickness. Pressure member 30 is similar in construction to pressure member 29. As the parts function similar .to the parts of the pressure member 29, similar partsof pressure member 30 and -pressure memberA 29 are provided with similar numbers. t

Pressure means 28, which is positioned on the other side of,cutter head I3 from the pressure arcaico means 21, is preferably in the form of a shoe 42 pivotally secured to the lower bed I2 on pivot 43. Ar spring 44 resiliently urges the end portion 45 downwardly and the toe 46 of the shoe 42 upwardly, thereby urging lumber upwardly against the xed bed II. l the downward movement of the end portion 45 of the shoe 42. Said stop means may be in the form the adjustable 'screw shown.

iBy turning adjusting screw 22, the peripheral portion of the cutting knives I9 of the cutter head I3 may be adjusted above the bed plate I2 .so that lumber will be 'cut on a level above the bed plate I2 and such lumber will be urged clear l of lthe forward end portion 'of the bed plate I2 by the pressure means 21 and 28.

operatively positionedabove fixed bed plate I2 Vis a planing device. Such planing device may be in the form of a driven'cutter head I4 lprovided with cutter knives 49, the peripheral Stop means 41 limits` K of the arm 48 connected to xed bed plate I2 and portion of the cutter knives being positioned in spaced relation to the fixed be'd I2 to provide the final predetermined vthickness of the lumber. The pressure means urging lumber downwardly against bed plate I2 may be in the form of a pressure member 50, having a shoe 5I pivotally connected to one end of the pressure member 50 and the other end of the shoe pivotally connected y 60 with lever arm 6I of link 56. The downward movement of the pressure member 50 is limited f by stop 62 engaging portion 63 of link 51.

In view of the fact that the space between the bed plates II and I2 is-greater 'than the thickness of the lumber passing therethrough, and in view of the fact that the lumber is urged upwardly by pressure means 28 and then downwardly by pressure member 50, the lumber is flexed. The cutter head I3 preferably cuts approximately .020 of an inch above the bed plate I2 with 18 inches between the cutter heads" I3 and I4 for onf an inch fir lumber, and if so adjusted a substantial air space .020 of an inch appears between the board and leading end of the bed plate I2. The adjustment may be such so the cutter head I3 cuts only slightly above the bed plate I2 and thereby only places the lumber under an appreciable longitudinal strain or if the distance that'the cutter head I3 cuts above bed plate I2 is increased, the lumber will be flexed an amount depending upon the amount of such adjustment. Throughout this application such vflexing or'strain of the board will be referred to as longitudinal flexing or longitudinal strain.

In the form of our invention shown in Figs. 1 to 3, a resilient pressure means 64, which may be similar to the pressure means 28 is employed. Such pressure means 64 operates upon lumber directly after the same has passed cutter head I4. Thus, resilient pressure means are provided on each side of the cutter I4 urging the lumber against the bed plate I2. 4By providing such e means all tendency of the lumber to chatter or vibrate is entire removed. Also such pressure means may operate for a long period of time without adjustment. .'Furthermore. such a 75 lumber against the lower bed plate after the lumber has passed the cutter head II.

The pressure means 6I has a foot portion 65 mounted on a pivot 86., A spring 61, exerting pressure against an extension 68 of said pressure member, urges the toe 69 thereof in contact with the traveling lumber. The stop screw 10 supported by a bracket 'II limits the pivotal movement of the pressure means GI.

For lassisting in the removal of the lumber from the machine it is preferable that driven feed roll I'I be mounted for vertical movement by pivoted frame member 12 and link 13 which is pivotally connected with frame memberv 12 and .urged downwardly by spring 14 which abuts chine. The lumber leaving the planing unit of the machine veryoften enters directly into the matching units of the machine. In such an event the feed rolls I1 and I8 might be conveniently disposed of or positioned after the matching cutter heads in the line of travel of the lumber. y

Referring to the feed rolls vI5 and It, which tend to urge material through the machine, the lower feed roll I6 is resiliently urged upwardly as by a spring 1t, which exerts a pressurejagainst a block 11. The block 11 is slidably mounted in a slot 18 in the main framevZI, and the feed roll I8 is journaled in said block 11. nism is necessarily in duplicate at each end of the feed roll I6. The upward movement of this feed roll I6 may be limited by the engagement of the block 11 with the upper end of the slot 18.

The upper'feed roll I5 is rotatively mounted in vertically adjustable frame means 19, which is in duplicate at each end of the feed roll I5. Frame .means 19 ls slidably disposed in guide means 80 and said frame 19 is'vertically adjustable by means of an upright adjusting screw 8l,

which has a threaded connection with 'frame spiral gears 83.

This adjustment provided for upper feed roll I5 makes possible the adjustment of said feed means 19 and is driven from a shaft-82 through roll I5 along with the adjustable bed plate II,

different pieces of stock used in the production of a finished product of any given size,'whi1e the 'adjustment of the upper'feed roll I5. changes the machine so that kit will accommodate a different size stock to obtain a different size product.

Assuming that a finished lumber size of 50/64 of 'an inch is desired, the cutter head I3 is vertically adjusted relative to the bed I2 by means of l screws 22 and then the upper bed plate II is ad- .iusted and its position -fixed so that the distance between the bed plate and the peripheral portion 'of the cuttingknives I9 of cutter head I3 is set "at a predetermined distancesuch as 53/64 of an .inch or Y /64 of an inclfi' over the desired final predetermined thicknessf This distance is preferably the minimum amount which is sufficient Vto clear up the saw-cuts and other blemishes on the facev of the ,stock and of course |will vary This mechaperio ter knives I9 with the condition or roughness of the stock. Assuming that 3/64 of an inch is allowed for surfacing the face then all excess of the stock over l53/64 of an inch will be removed from the back by the operation of cutter head I3 as the stock is held upwardly against bed plate II by pressure means 21 and 28. As the stock passes under shoe 5I it will be flexed and is transferred from the upper bed II to the lower bed I2. The distance between the peripheral portion of the cutting knives I9 of the cutter head It and the bed plate I2 is set at the exact dislance of the desired thickness of the final product. Again the peripheral portion of the cutting knives I9 has been set at a predetermined distance away from the bed pl-ate I2 and the lumber stock has been forced against the bed plate I 2. By this means the lumber is finishedto an exact l final predetermined thickness and is finished while the usually smooth previously surfaced back is held against a bed plate. The maximum amount of cutting obtained by the cutter head It is predetermined by the difference between the spacing of the peripheral portions of the cutting knives I9 of the cutter head It from the bed plate I2 and the cutting knives I9 of the cutter head I3 from the bed plate I I. By thus limiting the cutting action of the cutter knives 89 they are able by virtue of the almost constant or uniform depth of cut to do a better grade of work and produce a better finish on the face of the lumber, than the work done by machines of the prior art.

Furthermore, as all of the excess of the lumber stock over a preliminary maximum thickness is removed by the cutter head I3, any great Wear caused by too heavy and too light cutting falls on thecutter knives I9 of the cutter lead I3.

This is not objectionable a's the condition of the back is of secondary importance. Should the distance between the peripheral portions of the cutter knives I9 and the bed plate II vary because of wear due to the heavy and light cutting being done, such wear will cause only a variation in the preliminary predetermined maximum thickness. Thereafter, as the lumber stock is cut to final thickness by the cutter head I4, such variationswill not be sufficient to materially change the amount of cutting being 'done by the cutter head I4 and the cutter head I4 will continue to cut only a sullicient vamount to surface the stock to the exact final predetermined thickness. Thus the cutter head I4, taking an almost constant depth of cut, is working under ideal conditions and will not require suchfrequent sharpening of the knives and consequent frequent adjustment, as is necessary on the planing devices ci the prior art. In other words, as the work of the cutter head I4 is reduced to a minimum and is almost constant, the wear aorded the cutter knives 49, because of vthis uniformity in depth of cut, is educed to a minimum, and the xed adjustment or set, which determines the final size of the product will be maintained over long of time, in comparison to the prior art ymachine This results in a superior product and eliminates any of the costly idle periods here- The bed pl Ate I I is adjusted relative to the cut` y means of an adjusting screw 84, which is threaded through a worm gear 85. 'I'he worm gear 85 is positioned between two xcd lugs 86 on the adjustable frame 58, which frame 58 is slidable vertically in an extension 81 of the main frame 2|, see Fig. '7. The worm gear B5 is .mshed with a worm 88 on a shaft 89, having suitable means as a square head which may be readily engaged to turn the same. The adjusting screw til extends downwardly and is connected by spiral gears 90 and 0I with the adjusting shaft t2. The lower end of the adjusting screw 8d is preferably keyed to spiral gear 9| and is journaled in bearings which prevent vertical movement of the screw dll. The frame 58 is integral with or rigidly secured to the bed plate II, and the shaft d@ is journaled in said frame 5t. By placing a suitable wrench or tool on the square end of the shaft it@ and turning the same, it is possible to adjust the bed plate II toward and away from the cutter head I3. Also by rotating adjusting shaft d2 and turning the adjusting screw ed, it is also possible to adjust the be'd plate ii relative to the cutter head I3. This provides for an independent adjustment of the bed plate li by means of rotating of shaft 09 and also for an adjustment of said bed plate II, together with feed roll i5, cutter head Ii and pressure member til upon rotation of adjusting shaft 82 as hereinafter set forth. The pressure member 50 being mounted on the frame 50 will be adjusted simultaneously with the hed plate li.

The nishing cutter head Ill is -mounted in frame member 92 and this frame member 92 is connected as at 93 with an adjusting screw Q0. Adjusting, screw @Il is threaded through a spiral gear iid which is supported between frame lugs et and meshes with another spiral gear 91 on the adjusting shaft t2, see Figs. 1 and 8. This supports the adjusting screw '9d so that when said screw` is turned and the spiral gear 05 is nonrotatably held, the adjusting screw 9d will be moved vertically. Also when the adjusting screw et is held nonrotatably and the spiral gear 95 is rotated, said adjusting screw will be moved vertically. The adjusting screw 9d has a worm gear @t splined thereon and positioned between two xed frame lugs 99. A hand adjusting means in the nature of a worm |00 meshing with worm gear98 and mounted ona shaft.v IOI, having a square end portion by which it may be turned, is .provided for adjusting shaft 94. .By turning the shaft |0| manually, it is possible to adjust the frame 92 and nishing cutter head I4 inde-4 pendently of other parts of the machine. By rotation of adjusting shaft 82 it is possible to adjust frame 92, finishing cutter head I4, resilient pressure means 64, along with upper bed plate II, upper feed roll I5, and pressure member 50.

Adjusting shaft 82 is preferably power driven and may have a driving connection with a motor |02 by means of .bevel gears |03 and spur gears |04, |05A`and jl06, spur gear |06 being on the shaft of motor |02. Motor |02 illustrates a convenient form of prime moover and is connected to any source of electrical power by suitable means` '5(not shown); .,It will be 'thus seen'that feed roll I5, bed plate II, pressure member 50, cutter head I4, and pressure means 64 may be moved together so that the machine may be adjusted to produce various thickness of stock, suchas one inch, two inches, or any other desirable thickness within the rangen .of the machine. AXfter the machine is adjusted by the power means to the approximate thickness of a particular stock, then a more accurate adjustment is provided so that the ,exact distancejbetween the cutter head vI3 and the bed vplate II may besuitably fixed to provide a prellminary predetermined,thickness of stock, and

thedistance between the cutterv head I4 and the bed.' plate n may be'suitablyiixed 't0 provide s aioaiee final predetermined exact thickness of nished stock. Also the cutter head I3 is adjusted relative to the bed plate AIt? to provide the odesired flexing of the lumber.

Vertically adjustable bed plates and cutter heads are old in the art, and any of .the suitable devices of the art may be used to connect the adjustable bed plate II with the main frame 2I-. Also any suitable mounting means may be used to connect the adjustable cutter heads I3 and I4 with the main frame 2 I.

In the operation of the device shown in Figure l, it will be noted that allrstock in excess of the preliminary predetermined maximum thickness is removed by the rst cutter head as the lumber is urged away from the cutter head toward an opposed fixed bed plate and the final maximum thickness of the lumber is determined as the lumber is iiexed and urged in the opposite direction against a xed bed plate with a cutter head operating in spaced relation to the last mentioned bed plate. Throughout the description, for the purposeof clearness, we have referred to the bed plate II as an upper bed plate, and the bed plate I2 as the lower bed plate. It is obvious that the principle of our machine will operate in the event that the machine is rotated on the longitudinal axis of the passageway of the lumber. It is preferable, for reasons heretofore explained, to operate with bed plate II as an .upper bedplat and bed plate I2 as a lower bed plate, so that the lumber will be finished face up and readily available for examination. Howeverfif the machine is rotated on the 4longitudinal axis @of the lumber passageway, it will function in a similar manner, except that the face of the lumber will be positioned according to the extent of rotation.

In Figure 1, |01 illustrates a board passing through the machine where a relatively heavy cut is removed from the back of the stock by cutter head I3, while the maximum predetermined cut of the finishing cutter head I4 obtains. Board |08, which is illustrated directly behind board |01, is of a greater thickness than the board |01 and illustrates a rocking action by the pressure member 29 and illustrates the feed roll I6 being moved downwardly to accommodate such thicker board |08. Obviously, a thicker cut y must be taken from the back of board |08 by cuttei head I3 to remove all excess over the preliminary predetermined maximum thickness, while only the difference between the preliminary predetermined maximum thickness and the final predetermined maximum thickness will be removed by the finishing cutter head I 4.-`

. In Figure 2, we have shown a board |09 of a thickness, before passing through the machine,

l substantially equal to the predetermined prelimiit is flexed and urged downwardly against the bed plate |2'and thereafter cutter head I4 removes all excess over the final exact predetermined maximum thickness, thereby providing a periect face for the stock and stock of uniform thickness. f

The illustration in Figure 2 shows a useful work accomplished by our machine, which has been heretofore impossible in the art. vA boa-rd is provided with a perfect face and a predetermined uniform thickness, although the same has skipped spots on the back. Theskipped spots on the back do not detract from theV grade of the lumber, and first grade lumber may be obtained from thin stock which was heretofore render/ed useless by the machines 'of' the prior at, which took or reserved to take a predetermined/cut of a certain thickness from one surface/of the stock and attempted to thickness the lumber by planing the other surface of the stock,

In Figure 3, we have shown a board IIB which is less than the final predeterminedthickness of the lumber which is being produced'. With such a board H0, the 'pressure means 2l and 28 urge the'board Il@ upwardly against bed plate II and clear of the peripheral portion of thecutter knives I 9; Thus, the cutter knives I9 do not cut the board III). As the board IIB reaches pressure member 5u it is flexed and urged downwardly against bed plate I2 and clear of the peripheral portion of the cutting knives e9. Thus the cutting knives #i9 do not cut the board IIIII.

Again we have illustrated a useful operation which is impossible in machines of the prior art, as such machines take a fixed cut regardless of the thickness of the stock. A board, suchas I IIJ, will be useful for thinner stocks, but any unnecessary cut from such board renders it thinner and less useful, If it is not available for a predetermined thickness of stock, such as 50/64, the operationl of our machine is to pass such stock directly therethrough without reducing the thickness of the stock. In other words, if stock is too thin we have eliminated the heretofore bad functions of the machines of the priorL art and we do not make this thin stock thinner and further-dete- 5 riorate its value.

In Figure'fl, we have illustrated a modified form of our invention, where the resilient pressure member SII is replaced by the shoe III. This shoe I II is mounted with its lower surface II2 positioned in a horizontal plane substantially tangent to-the peripheral path of the cutting knives 49. The shoe II I is adjustably mounted in frame I-I3 by means of set screw IIIl and adjustable screw IIS. The space between the shoe III and the lower bed I2 may be adjusted so that the upward movement of the lumber, as it is passing the cutter head I4, is limited to prevent the lumber from chattering or being gouged by the cutter head I4. Frame `I I3 corresponds to frame 92 of Figures l, 2, 3 and 7. j

In Figure 5 we have illustrated in end elevation an unfinished piece of stock. As the stock dries out the moisture content of the stock tends to centralize as indicatedgenerally at IIB. As such rough stock is cut it will' be noted thatthe cut indicated'by dotted vline I I1, removing a minimum portion from the nished face of the stock, does not cut so 'near to the moisture content of the stock, which has been driven toward the cen" ter by the drying process, as does the thicker cut from the back. On the other hand, the thicker cut on dotted line IIB will cut into the substantially centrally disposed moisture IIB, leaving a moisture content along the cutting line II8. As the' piece of lumber illustrated in Fig.- ure 5 further dries out, the moisture content is again driven toward the center, causing a shrinkage along line II8. When two boards, such as the flooring indicated in Figure 5, are placed alongside. of each other, as are shown in Figure 6, the shrinkage along the back face will cause an opening at seam lill. lInour device we have provided means for always removing the excess from the back of the stock, and only a predetermined maximum amount of stock may be removed from the face. This maximum cut which mayl be taken from the face of the stock may be limited so that it is notl suicient to outI close enough to the centrally disposed moisture to cause a damaging shrinkage along the face. On the o th'er hand, if a deep cut is necessary to'remove the excess stock to obtain a proper thickness, we provide a means for always removing this excess from the back, so that if the board does shrink by reason of relocating the moisture content after` the board has been planed, it will tend to concave ythe back of the stock and may possibly cause openingsl at the seams, suchasI I9. l These openings on the back will not open seams which will show on the top surface of the floor or other places where the stock is used, and will not cause damage, while on,the other hand, if the openings at the seams were on the face, a very serious damage wouldresult. lIn the machines of the prior art no provision has been made for limiting thecuton the face and positively insuring that all excess will be removed from the back of the stock. Therefore, openings at the seams,

very often appear in the top surface of a floor o made of stock, cut by the prior art machines, when the moisture content is later reduced. Such seams ruin the door or other finished Work made v chines, the lower cutter head cuts too deeply into the trailing end of thestock, causinglend snipping. If such stock is surfaced with the curve or bend pointing upwardly", then in such. prior art machines, the upper cutter head cuts too deeply into the forward end of the stock, again causing end shipping. In our device ,this end shipping, even onbadly bent stock, is eliminated by placing the lumber under longitudinal strain or the flexing of the lumber. For example, if the trailing .end of a piee of lumber stock is downwardly curved, the stock will ube held up against bed plate II by pressure means 21 and 28 and by the longitudinal stiffness of the lumber which is utilized because o flexing action. As soon as the trailing end passes off the pressure means 21, the longitudinal stiffness of the board which is utilized by the exing action will keep such trailing-end in itsproper position against bed plate II. likewise if the lumber is bent upwardly at the leading-end, the flexing will maintain such end portion against bed plate I2 and prevent endsnipping at the forward end.

It is preferable in most fully realizing the benets of our invention to have the pressure means followi the rst cutter, as pressure member 28, in the form of a resilient member.' This provides for adapting the apparatus to operate on boards which are of such thinness` that .they may not be cut at all by the cutter head I3. This also permits automatic takeup for wear of cutting knives I9 and thereby provides the desired looseness of fee'd at all times.

As the longitudinal passageway formed between bed plates I I and I2 may be substantially greater than the size of the lumber passing therebetween, our device not only provides for flexing the lumber stock but provides for free feeding. As previously pointed out, the cutter head I3 sizes the lumber stock to' a preliminary predetermined maximum thickness. Inother words, this cutter isoperating under adverse conditions, in that the cut ymay be very thick and the work thereonl increased or the cut may be thin so that the knives I9 of the cutter head I3 are operating to scrape off the dirt and grit accumulated on the stock, both of which conditions cause considerable wear on the knives of the cutter head I3. As the knives of the cutter head I3 wear, the maximum predetermined preliminary thickness of the board will increase. By providing a maximum preliminary predetermined thickness of the board, which is substantially less than the size of the longitudinal passageway between bed plates II and I2, considerable wear may be had on the knives of the cutter head I3 without any tendency of the boardto pinch or feed tightly through said passageway. In case of tight feeding the following objectionable results occur: (a) The operation of the machine must be frequently periodically interrupted to provide for adjustment of the cutter head I3; (b) If you attempt to force the lumber through a tight feed by the use of suflicient pressure to grip the lumber, there results a compression of the ber's of the wood which results in a raised grain subsequent to the planing operation. It should be noted that stock to be planed or finished is ordinarily kiln dried and is more readily injured than lumber from which the moisture has not been A removed; (c) If you dont increase the pressure of the feed rolls on the stock, 'so as to provide uniform travel of the lumber through the machine, despite the tight feeding due to the growth in the thickness incident to the wearing of the knives, then there results the usual defects of such non-uniform feeding, such as burnishing and unevenness of nish.

As pointed out, the knives on the cutter head I3` may wear considerably without requiring sharpening thereof, adjustment o"f the machine,

termined thickness may increase.

substantially vary the ideal conditions under which the cutter head I4 is operating, and consequently the cutter head Il will accurately nish lumber to a predetermined nal thickness for long periodsI of time without adjustment or sharpening.

Our invention in providing for flexing and the utilizing of the longitudinal stiffness of the stock not only prevents end snipping and provides loose feeding but provides for better grade of face surfacing. This is accomplished in part by the ideal conditions under which cutter head I4 Obviously, changes may be made in the forms,

dimensions 'and arrangement of the parts of our invention-without departing from lthe principle thereof, the above setting forth only preferred forms of embodiment.

We claim:

1. A planing machine embodying an upper fixed bed and a lower xed bed positioned in spaced relation and forming therebetween a longitudinal passageway vfor moving lumber, said beds forming means for limiting the upper and lower vertical positions respectively of lumber passing through said passageway; a cutter head operatively positioned below and in spaced relation to said upper bed, said cutter cutting in a plane above the supporting surface of said lower bed; pressure means operatively positioned as respects said cutter head urging moving lumber against said upper bed at the time said lumber is passing said cutter head; another cutter head longitudinally spaced as respects said `first cutter head and operatively positioned above and in spaced relation to said lower bed; and other pressure means longitudinally spaced as respects said first mentioned pressure means and operatively positioned as respects said last mentioned cutter head urging moving lumber against said lower bed at the time said lumber is passing said last mentioned cutter head, said respective pressure means being spaced longitudinally a sufficient distance as required by the thickness of the lumber to permit exing of the lumber therebetween and said respective pressure means being positioned on opposite sides of said longitudinal passageway and each acting toward said longitudinal passageway, whereby lumber may be flexed and transferred from one of said beds to the other.

2. A planing machineA embodying a main frame; an upper fixed bed adjustably mounted on said frame; a lower fixed bed mounted on said frame in spaced relation from said upper bed and forming a longitudinal passageway for moving lumber, said beds forming means for limiting the upper Land lower vertical positions respectively of lumber passing through said passageway; means for moving` lumber through said passageway; a cutter head operatively positioned below and in spaced relation to said upper bed, said cutter cutting in a plane above the supporting surface of said lower bed; pressure means operatively positioned as respects said cutter head urging moving lumber against said upper cbed at the time said lumber is passing said cutter" head; another cutter head adjustably mounted on said framev and positioned in longitudinal spaced relation as respects said first mentioned cutter head and operatively positioned above and `in spaced relation to said lower bed;,other pressure means adjustably mounted on said frame and operatively positioned as respects said last mentioned cutter head urging moving lumber against said lower bed at the time said lumber is `and the lower bed, together with their respective planing devices, may be adjusted to permit flexing-of the lumber from one bed to the other.

3. A planing vmachine embodying longitudi-v nally spaced apart first and second beds forming therebetween a longitudinal passageway. foi" moving lumber; a planing device positioned in spaced relation to the first of said beds for planing the back face of said lumber and cutting said lumber to a. predetermined initial thickness, said planin-g device cutting in a plane more adjacent the rst bed than the distance between beds; re-

siliently supported Yflrst and second pressure means operatively positioned respectively upon each side of said planing device, urging moving lumber against the first bed at the time said lumber-is passing said first planing device, the second of said pressure means, while urging said lumber against the iirst bed, also functioning to hold the lumber above the rst end portion of the second bed; a planing device to plane the face of the lumber longitudinally-spaced as respects the iirst planing device and in operative spaced relation to the second bed; a third resilient pressure means operatively positioned immediately in fronty of said second planing device urging said lumber against the second bed at the time said lumber is passing said second planing device, the oppositely directed pressures of said second and third pressure means functioning to impart a exing to said lumber, .whereby the longitudinal stiffness of the said lumber is utilized to assist .in holding the same firmly against fluttering and vibrating; and

` back face and cuttin-g the lumber to a predetermined initial thickness, said cutter cutting in a plane above the supporting surface of said lower bed; a first and second resilient pressure means operatively positioned `respectively upon each side of said planing device urging moving lumber against the upper bed at the time said lumber is passing said planing device, the second of said pressure means, while urging said lumber against the upper bed, also functioning to hold the lumber away from the rst end portion of the lower bed, a second planing device longitudinally spaced as respects the iirst planing device and in operative spaced relation to the other of said beds for planing the face of the lumber; a third resilient pressure means operatively positioned immediately in front of said second planing device urging said lumber against the lower bed at the time said lumber is passing said second planing device, the oppositely directed pressures of said second andthird pressure means functioning to impart a flexing to said lumber, whereby the lon- .gitudinal stiffness of the said lumber is utilized to assist in holding the same firmly against fluttering and vibrating; and means positioned im mediately behind said second planing device limiting the upper verticall position of said moving lumber while said lumber is passing said second planing device.

5. 'I'he method of planing lumber having a rough thickness greater than the -nished 'thickness, comprising subjecting traveling lumber to a planing device to remove all excess over an initial predetermined maximum thickness from the back face of said lumber while said'lumber is urged in one direction against a fixed bed; progressively longitudinally flexing said lumber during its travel; and subjecting said lumber during its travel to a planing device to remove all "excess over a iinal` predetermined. maximum thickness while said lumber. is urged in the opposite direction against a iixed bed.

6. The method of planing lumber having a rough thickness greater than the liinished thickness comprising planing one face of traveling lumber at one area on the line of advance of the traveling lumber, progressively flexing said traveling lumber at danother areain the line of advance of the traveling lumber, and planing the opposite face of said traveling lumber at still another area in the line of advance of the traveling lumber.

7. In a planing machine, the'combination of a first bed and an opposite second bed forming therebetween a longitudinal passage for movinglumber, said beds forming means for limiting the movement of lumber in opposite directions; a planing device operatively positioned opposite one of said beds, said planing device cutting in a plane more adjacent the said one bed than the distance between beds; a'second planing device operatively positioned opposite the 'other of said beds; a pressure means in advance of each of said planer devices to hold the work against the beds respectively; anda resilient pressure means located opposite the rear portion of the first of said beds and-between the iirst planer device and the front end of the second bed, the said resilient pressure means and the pressure means in advance of the second planer deviceracting Ito flex the lumber -as it passes from one, bed to the other bed.

8. In a planing machine, the combination of upper and lower beds forming a longitudinal passage ior moving lumber; a lower cutter opposite the upper bed, said cutter cutting in a plane above the supporting surface of said lower bed; an upper cutter opposite the lower bed; a pressure means in advance of each cutter to hold the work against the beds respectively; and a resilient pressure means located under the rear portion of the upper bed and between the lower cutter and the front end of the lower bed, the said resilient pressure means and the pressure means nin advance of the upper cutter acting to flex the lumber as it passes from one bed to the other bed.

9. A planing machine embodying a first fixed bed; a first cutter head operatively positioned in spaced relation to said rst bed; pressure means operatively positioned as respects said iirst cutter head urging moving lumber against said rst bed at the timel said lumber is passing said first cut-l ter head; a second iixed bed positioned in spaced relation to the first fixed bed and forming between said beds a longitudinal passageway for moving lumber, said beds forming means for limiting the transverse positions of lumber passing through said passageway, said second ilxed bed being transversely positioned more remotely as reSpeQlS Said first bed than the plane of cutting.

of said rst cutter head to thereby permit lumber to be placed under a longitudinal strain as it is transferred from one of said beds to the other; a second cutter head longitudinally spaced as respects said rst cutter head and operatively positioned in spaced relation to said second bed; and another pressure means operatively positioned as respects said second cutter head urging moving lumber against said second bed at the time said lumber is passing said second cutter head," said respective pressure means being longitudinally spaced and acting in opposite directions.

10. A planing machine embodying an upper fixed bed; a cutter head operatively positioned below and in spaced relation to said upper bed; pressure means operatively positioned as respects said cutter head urging moving lumber against said upper bed at the time said lumber is passing said cutter head; a lower fixed bed positioned in spaced relation to the upper fixed bed and forming between said beds a longitudinal passageway for moving lumber, said beds forming means for limiting the upper and lower vertical positions respectively of lumber passing through said passageway, said lower xed bed being positioned below the plane of cutting of said lower' cutter head to permit lumber to be placed under a longitudinal strain as it is transferred from one of said beds to the other; another cutter head longitudinally spaced as respects said first cutter head and operatively positioned above and in spaced relation to said lowei` bed; and another pressure means operatively positioned as respects said last mentioned cutter head urging moving lumber against said lower bed at the time said lumber is passing said last mentioned cutter head, said respective pressure means being longitudinally spaced and acting in opposite directions.

11. In the method of planing opposite surfaces of lumber the steps of providing a longitudinal passageway for moving lumber, between opposed bed plates, said passageway being of a size substantially greater than the thickness of the lumber passing therethrough; and longitudinally flexing the lumber to engage a portion of the moving lumber against one bed plate and to engage a longitudinally spaced portion of the moving lumber against the other bed plate whereby minimum frictional resistance to travel of the lumber obtains.

l2. The method of preventing end snipping of lumber in double surfacing machines comprising, providing a longitudinal passageway for moving lumber between opposed bed plates having longitudinally spaced lumber supporting surfaces; longitudinally flexing the lumber between the two bed plates having longitudinally spaced lumber supporting surfaces causing the lumber in one portion of its travel to engage one surface thereof with one bed plate and in another portion of its travel to engage the other surface thereof with the other bed plate; and subjecting the nonengaging surface ofthe lumber to a planing device at that portion of the travel of the lumber when the opposite surface is engaging one of the bed plates.

FREDERICK A. NICHOLSON.

WILMOT T. PRITCHARD. 

